The major focus of the Patient Core will be the recruitment of patients to support genetic studies. Accordingly, the Patient Core will actively recruit two specific groups of patients: l) African American hypertensive sibling pairs - selected patients with early-onset, moderate-severe hypertension will be recruited from an enormous hypertension clinic in Chicago by a group led by Drs. Bakris and Black; and 2) multiplex African American kindreds with end-stage renal disease - patients will be recruited by a group of investigators based at Yale from a large, multicenter dialysis network population with subsequent identification and collection of affected relatives. The collection of blood samples from these patients will provide ample substrate for genetic studies detailed elsewhere in the SCOR; specifically Projects l, 2, 3,4, 5, and 6 will use patient samples from the Patient Core for genetic linkage studies, as will the Genetics Core. The Patient Core will also serve as the central database for all collected patient information from the various projects in the Yale SCOR. The Core Administrative Assistant will be responsible for organizing the gathered data into the database to provide all of the study investigators rapid access to this important resource. All patient samples collected in the SCOR will first be entered into the database an then be assigned a numerical code to preserve the patient's anonymity during subsequent testing procedures. Lastly, the Patient Core will act in a supporting role to assist the various investigators with recruitment of patients from kindreds with confirmed or suspected Mendelian forms of hypertension and salt wasting. Project investigators will have access to all of the resources of the Core to expeditiously achieve their patient recruitment goals.